There are mods that have amended how many starbases you can have in a well, some as many as 4, 5 and 6, but to be honest that is overkill, and makes the game too easy.
But when i started i was really really lousy, haha, am still not too hot, but am getting better, but there was this mod that made ships half cost, and it was wonderful! At least for the first month, after that it was too easy and really not very fun, so i unplugged that mod and got one that was a lot different. I think it was 7DS, and that was a lot of fun and stayed for for quite a bit.
After that i started making my own mods, and it was easier to make them harder, or give slight edges which made the game still very challenging, but also different than the standard game. Also, after awhile, modding was almost like playing, i spent a lot of time at it, and it was like winning when i could figure something out, and like losing, when i couldn't.
I have been in school heavy over the summer, and my modding has almost stopped, but not for good, just until the semester ends and life gets a little less hectic.
If you look on Google, you should be able to find a starbase mod that gives extra sb's per planet if that is what you want, and lots of other things as well. Enjoy,